1. Field of the Invention
The present invention relates to an adaptor and coupling structure of a vehicular wiper arm, and more particularly, to a wiper arm adaptor with an altered pin coupling structure that is capable of coupling to a variety of wiper arms without using rivets, is easily coupled without manipulating the pin of a wiper arm, is coupled to pivot the adaptor centrally around a wiper frame, and increases the pivoting supporting strength of a wiper.
2. Description of the Related Art
A vehicular wiper, as shown in FIGS. 1 and 2, couples a wiper arm (that moves a wiper blade) to a frame 11 through an adaptor 10.
FIG. 1 shows a structure for coupling an adaptor 10 to a frame 11 by permanently fixing a rivet 12a at the center of a mounting slot 12. Here, the rivet 12a functions to fix the adaptor 10 and reinforce the frame 11. Because the rivet 12a needs a separate riveting process to couple to the frame 11 (increasing the manufacturing process), it also requires additional parts, which can interfere with adjacent parts and limit the degree freedom in wiper design.
FIG. 2 shows another coupling structure of a wiper frame 11 to a wiper arm. A mounting slot 12 is first formed in the wiper frame 11, and an adaptor 10 is positioned therein. A fastening pin 13 is then used to fasten the adaptor 10 to the frame 11.
The structure of the wiper arm 14 for coupling to the adaptor 10 can adopt various configurations and shapes. The shape of the terminal coupling portion of the wiper arm 14 for coupling to the adaptor 10 can be grouped into two general categories: hooked-type and pin-type connectors.
FIG. 3A shows a hooked-type connector at the end of a wiper arm 14 plate having a coupling slot 15 that fits over and couples with a protruding portion formed on the adaptor 10.
FIG. 3B shows a pin-type connector having a pin 16 protruding from a side at the end of the head of the wiper arm 14, where the adaptor 10 is coupled to the pin 16.
The coupling direction and structure of the wiper arm 14 is formed to correspond to the shape of the coupling portion at the end of the wiper arm 14.
That is, if the wiper arm is a hooked-type arm, it inserts into the adaptor 10 from the top thereof; however, a pin-type arm inserts the pin 16 of the wiper arm 14 from the side of the wiper blade frame, as shown in FIG. 4.
Thus, because the role of an adaptor 10 is to mount the wiper arm 14 to the frame 11, adaptors have been developed to accommodate the mounting of a variety of wiper arm 14 structures and specifications in both hooked and pin-types.
FIG. 4 shows a wiper arm frame with two small pin holes 18 and 19 formed therein at different locations to couple with a pin 16 of a wiper arm 14 having a different diameter.
However, because the two smaller pin holes 18 and 19 come in only two sizes, only two sizes of wiper arm 14 pins are compatible with this type of frame 11. Also, because the central hole of the frame 11 has a fastening pin 13 inserted therein for fastening the adaptor 10 to the frame 11, this hole cannot be used. In order to couple the pin 16 of the wiper arm in the adaptor 10, the pin 16 is inserted in the pin hole 18 and 19, and the corresponding hole of the adaptor 10 must be aligned precisely for the pin 16 to pass through, so that the coupling is inconvenient. The adaptor 10 functions to simply support the wiper arm 14 to be able to pivot against the frame 11, and is seated and fixed to the frame 11 by only the fastening pin 13. Therefore, it is difficult to maintain a firm coupling, and the supporting strength weakens over time. Because the fastening pin 13 used is generally a rivet, the riveting process permanently fixes the frame 11, so that reinforcing of the frame 11 necessitates a coupling of the adaptor 10 and a separate riveting process, increasing the number of parts and complicating the process. The pin 16 of the wiper arm 14 cannot be inserted into the riveted fastening pin 13, so that a small area must be used, which limits freedom of design.
Furthermore, the adaptor 10 does not have a role other than fixing the wiper arm 14 to the frame 11, and is located in an area subject to much wind resistance, so that it can cause wind-induced streaking and judder.